When a group of jellyfish moves together they could contribute to the large-scale mixing of ocean waters. Kakani Katija, a graduate student at the California Institute of Technology, believes it’s possible, based on her recent experiments with jellyfish blooms in a freshwater lake in Palau. Katija and her team studied how the movement of jellyfish impacts the water around them. Researchers placed a fluorescent dye in front of the jellyfish and observed what happened as the jellyfish swam through it.
The team found that the jellyfish are swimming through the dye, the jellyfish appeared to pick it up, tucking it in a space just behind their tentacles. As the jellyfish swam, they carried the dye (and water) along. By monitoring the variation of the dye color, the research team discovered that each jellyfish was carrying water for about 50 feet (15 meters) — many times the size of its body.
It is observed that it is a mechanism that would allow for animals to mix water efficiently when they swim. The new research, published in the journal Nature, would suggest that the mass movement of marine animals — even tiny zooplankton like krill — may play a significant role in churning the ocean. It may help mix cooler water with warm, and disperse salts, nutrients and pollutants across the various layers of the ocean, which is critical to the strength of ocean currents and the health of the marine ecosystems.
In one study published in the journal Science in 2006, a group of scientists reported that they had recorded enormous water turbulence in a fjord in Canada caused by a swarm of swimming krill.
